Hydrophilic colloid silver halide emulsion hardened with a bis(vinyl-sulfonylmethyl) ether and an acrylic compound

ABSTRACT

Certain blends of A. ACRYLIC HARDENER, PLUS B. BIS(VINYLSULFONYLMETHYL)ETHER EXHIBIT SYNERGISM WITH RESPECT TO CONTROLLING THE &#39;&#39;&#39;&#39;AFTERHARDENING&#39;&#39;&#39;&#39; THAT IS USUALLY OBSERVED WHEN, FOR EXAMPLE, GELATIN-CONTAINING COMPOSITIONS ARE CHEMICALLY HARDENED. The hardened gelatin compositions are particularly useful as emulsion layers in photographic elements.

States Patent Dallon et a1.

[ Nov. 26, 1974 HYDROPHILIC COLLOID SILVER HALIDE EMULSION HARDENED WITH A BIS(VINYL-SULFONYLMETHYL) ETl-IER AND AN ACRYLIC COMPOUND [75] Inventors: Dale S. Dallon; Mary K. De Seyn,

both of Rochester, NY.

[73] Assignee: Eastman Kodak Company,

Rochester, NY.

22 Filed: May 7, 1973 [21] Appl. No.: 357,975

3,635,718 l/1972 Froehlich et a1 96/111 3,640,720 2/ l 972 Cohen 3,642,486 2/1972 Burness et a1. 96/111 FOREIGN PATENTS OR APPLICATIONS 1,234,839 6/1971 Great Britain 96/111 Primary ExaminerDavid Klein Assistant ExaminerWon H. Louis, Jr. Attorney, Agent, or FirmJohn T. Lewis [57] ABSTRACT Certain blends of a. acrylic hardener, plus b. bis(vinylsulfonylmethyl)ether exhibit synergism with respect to controlling the afterhardening that is usually observed when, for example, gelatin-containing compositions are chemically hardened. The hardened gelatin compositions are particularly useful as emulsion layers in photographic elements.

8 Claims, No Drawings HYDROPHILIC COLLOID SILVER HALIDE EMULSION HARDENED WITH A BIS(VINYL-SULFONYLMETHYL) ETI-IER AND AN ACRYLIC COMPOUND This invention relates to compositions containing hydrophilic colloids such as gelatin which have been chemically hardened, to photographic emulsions containing such chemically hardened colloids, and to colloid/hardener admixtures useful in the manufacture of such hardened compositions. More particularly, this invention is directed to gelatin-containing compositions which have been hardened with a mixture of chemical hardeners, which mixture causes better afterhardening characteristics (in the hardened compositions) than can be obtained by use of either of the individual hardeners alone.

PRIOR ART The use of a natural polymer such as gelatin, alone and in combination with synthetic polymers as vehicles, particularly for photographic purposes, often requires treatment with a succession of aqueous baths of variable pI-I or of increased temperature during the development of the photographic article. Much work has already been done in treating natural synthetic polymers to improve their resistanceto water so that melting and an undesirable amount of swelling do not occur upon treatment thereof with aqueous solutions in processing operations or in hot drying. Various compounds have previously been found useful for treating photographic binders containing gelatin, for example.

Metallic salts, for instance, such as those of chromium, aluminum, and zirconium tend to react with and harden gelatin so very quickly that their addition, before shaping of the gelatin, in quantities required to achieve the desired hardening, involves the risk of premature coagulation of the gelatin solution.

Aldehydes such as formaldehyde are partly volatilized when materials containing them are dried, so that an accurate dosage is difficult to realize. Diketones of the 1,2-, l,4-type, among which group the quinones might be considered members, tend to cause a loss of speed of photographic emulsion upon storage.

Other hardeners require strong heating to produce a sufficient degree of hardening. Strong heating is undesirable in the case of photographic silver halide gelatin emulsions and layers since it may easily lead to a reduction in sensitivity and formation of fog.

Certain other simple organic hardeners require a high molecular weight ballast in order to render them nondiffusible which often causes adverse physical characteristics in the photographic emulsion. Also, such hardeners usually contain an undesirably low ratio of active hardening groups to ballast groups.

Many of the known hardeners act slowly, so that a long period of time is necessary to attain a sufficiently stabilized state of hardening. As a consequence, the development properties and sensitometric characteristics of a photographic emulsion layer containing these hardeners changes in a manner which cannot be controlled adequately. This undesirable effect is designated as afterhardening and is particularly detrimental because, as the layer continues to harden during storage, its permeability to processing solutions decreases. This causes unpredictable problems during development and adversely affects the speed of the photographic layer.

OBJECTS It is an object of the present invention to provide compositions containing hardened-hydrophilic colloid, which compositions have been chemically hardened by a synergistic combination of hardeners for the purpose of improving the afterhardening effect of such hardeners.

It is another objectof this invention to provide photographic emulsion compositions containing gelatin, which compositions can be coated on photographic supports and dried to yield hardened gelatin-containing layers which exhibit improved afterhardening properties.

It is still another object of this invention to provide novel methods for improving the undesirable afterhardening effects that are observed when gelatincontaining compositions are chemically hardened with certain hardeners.

Other objects will become apparent in view of the following discussion and claims.

SUMMARY OF THE INVENTION DETAILED DESCRIPTION OF THE INVENTION The use of mixtures, blends, or combinations of (a) bis(vinylsulfonylmethyl)ether with (b) an acrylic-type hardener selected from the group consisting of diacrylamide, N-methylacryloylacrylamide and N,N'- diacryloylurea as chemical hardener compositions in materials that contain hardenable hydrophilic colloid such as photographic layers has been discovered to result in substantially improved afterhardening", as compared to the degree of afterhardening that results from the use of either of the components alone. For example, such combinations have a synergistic effect with respect to improving afterhardening" of gelatin-containing compositions, which effect could not have been predicted from data previously available. This invention is particularly surprising in view of the observation that the synergism was not noted when the bis(vinylsulfonylmethyl)ether was replaced with its homolog, bis(vinylsulfonylethyl)ether in a test in which a combination of hardeners of the present invention improved afterhardening significantly.

- The use of bis(vinylsulfonylmethyl)ether as a hardener is described in U.S. Pat. Nos. 3,539,644 and 3,642,486. Diacrylamide and N- methacryloylacrylamide can be made by the method described in Volume 93 of Product Licensing Index, pages 52-53 (January, 1972). N,N'-diacryloylurea is described in U.S. Pat. No. 3,640,720.

The hardener mixtures described in this application can be used most advantageously with natural or synthetic polymers used as vehicles or binders in preparing photographic elements. Specific materials which can be hardened according to the practice of this invention include hardenable materials such as polymers, for example, gelatin, colloidal albumin, proteins, dispersed polymerized vinyl compounds, particularly those which increase the dimensional stability of photographic materials as exemplified by amine-containing polymers of alkyl acrylates, methacrylates, acrylic acid, sulfoalkyl acrylates or methacrylates, maleic acid, and the like.

The hardenable hydrophilic colloids useful in the practice of this invention are those generally known in the photographic art which can be hardened by formaldehyde. Thus, such hardenable hydrophilic colloids are materials such as gelatin which have melting points below about 65C, and preferably between about 27C. and about 50C. Typical examples of such materials can be found in the aforementioned US. patents.

The hardening mixtures described herein can be used in various kinds of photographic emulsions. In addition to being useful in orthochromatic, panchromatic, and infrared emulsions, they are also useful in x-ray and other nonspectrally sensitized emulsions. They can be added to the emulsions before or after the addition of any spectral sensitizing dyes which may be used. They are effective in sulfur and gold sensitized silver halide emulsions.

The mixtures of hardeners of this invention possess good hardening properties when they are blended with hardenable materials in any useful form such as in solution, emulsion or layer form. The mixtures can be used in any suitable hardening concentration which results in an increase in the melting point of the hardenable hydrophilic colloid of at least about 5C, including for example concentrations of from about 0.5 to about weight percent, based upon the dried weight of the hardenable material, and preferably within the range of from about 0.7 to 3 weight percent. These mixtures of hardeners are particularly useful in hardening hardenable photographic light sensitive emulsion layers; more particularly, those which contain gelatin and photographic silver halide.

In typical photographic usage, the mixtures of hardeners can be combined directly with the emulsion during its preparation, either as a mixture or as the individual components of the mixture. Then the treated emulsion can coated in layer form onto a substrate via conventional coating techniques and subsequently dried. The bulk of the hardening reaction (wherein the hardeners react with the hydrophilic colloid in the coated layer) preferably takes place during the drying step in such processes. The resulting dried, chemically hardened photographic elements can then be subjected to relatively higher processing (developing, fixing, etc.) temperature conditions than could otherwise similar, but unhardened, photographic elements without being physically degraded due to the higher temperature. Hardening can also be accomplished by contacting layer(s) of hardenable hydrophilic colloid material with an aqueous solution of one of the present hardener mixtures for a time, and at a temperature, which is sufficient to result in the desired degree of hardening (which can also take place during a subsequent drying step if desired).

tion can be coated on a wide variety of supports. Typical supports include those generally employed for photographic elements, as exemplified by cellulose nitrate film, cellulose acetate film, polyvinyl acetal film, polystyrene film, polyethylene terephthalate film, and related films of resinous materials as well as glass, paper, metal, wood and the like. Supports such as paper that are caoted with a-olefin polymers, particularly polymers of a-olefins containing 2-10 carbon atoms (for example, polyethylene, polypropylene, ethylene butene copolymers, and the like) can also be employed.

In addition to the hardening mixtures disclosed herein, photographic emulsions and elements can also contain other additives, particularly those known to be beneficial in photographic emulsions, as exemplified by spectral sensitizers, speed-increasing material, other hardeners, plasticizers, and the like.

The emulsions hardened by the mixtures of this invention can be used in photograph elements intended for color photography and thus may contain colorforming couplers. They may be used as emulsions to be developed by solutions containing such couplers or other color-generating materials, or they may be used as emulsions of the mixed-packet type. The silver halides employed in the photographic emulsions include any of the photosensitive silver halides as exemplified by silver bromide, silver iodide, silver chloride, silver chlorobromide, silver chloroiodide, and the like. The silver halides used can be those which form latent images predominantly on the surface of the silver halide grains or those which form latent images inside the silver halide grains.

Hardened emulsions obtained in accordance with this invention employing gelatin or other hardenable hydrophilic colloids may be used in diffusion transfer materials. In one form of this process the undeveloped silver halide is complexed in nonimage areas of the negative to form a water-soluble compound which is permitted to diffuse to a receiving layer in which said compound precipitates out as a positive metallic silver image. In other diffusion transfer processes, the final image is produced by diffusion of the developer, oxidized developer, coupler or dye, from the exposed and developed light-sensitive layer to a second layer in close proximity thereto. It is particularly advantageous to employ the hardener mixtures of this invention with hardenable substances or in systems comprising photographic emulsions, layers or solutions of hardenable matter where very little afterhardening is advantageous.

The actual amount of afterhardening a particular product might undergo is impossible to predict because the various conditions (temperature, humidity, pressure, and the like) to which such a product is exposed will determine the amount of afterhardening that takes place in any given product. However, a test has been devised in which the relative amount or degree of afterhardening" caused by various chemical hardeners can be determined. Also, experience has shown that average predictions can be made (based on the results of this test) with a fairly high degree of confidence that test results are fairly comparable to results that are experienced, on the average, in actual product usage. This test is termed the 7 Day Swell Test and is described in Example I, below. Ideally, the data for A% Swell in the aforementioned 7-Day Swell Test ideal figures meaning that very little to essentially no afterhardening took place under the test conditions. Whereas, many chemical hardeners are definitely com- In a test for afterhardening samples of the elements prepared using various hardeners and amounts of hardeners (shown in Table l, below) were incubated for seven days at a temperature of 49C and a relative mercially useful, the afterhardening effects of many 5 humidity of 50 percent. A check" sample of each was 1 of them nevertheless leave room for s1gn1ficant 1mp for the Same Perlod of at C and 50 Percerlt u provement. It 1s thls srgmficant improvement that can relat ve humldltybefore and after lmmerslo" be accomplished in accordance with the present invendistilled Water for 5 mlmltes at f" temperatu"6 tion. was determined by measurmg the thickness of the coated layers at these times. EXAMPLE I The hardeners which were tested were the following: Three layer photographic elements were prepared by I coating in a conventional manner on a cellulose acetate I diacrylamide photographic support the following layers: 11 his(vinylsulfonylmethyl)ether Ill bis(vinylsulfonylethyl)ether l a gelatm SuPlayer contammg 162 g gelatm per IV l,7-dichloro-3,3,5,5tctruoxo-3,S-dithiuhcptunc Square V Nmethacryloylucrylumitle 2. a green sens1t1ve silver bromiodide gelatin emul- VI y y Vll formaldehyde s1on contammg (per square meter), 1.45 g s1lver VI" mucuchlmic acid 323 g gelatin and 1.75 g of an incorporated magenta dye-forming coupler; and 3. a gelatin overcoat containing 32.3 g gelatin per Those data in Table l marked with an asterisk are desquare meter. rived from compositions of the present invention. Samln ad to a tro e Several elements ple numbers SI and 32 in Table l are results from comwere prepared using chemical hardeners and combinapositions which are the subject of copending US. Pat. tions of chemical hardeners. The hardeners were application Ser. No. 357,967 filed concurrently hereblended into the appropriate gelatin-containing disperwith, and sample numbers 34 and are results from sions shortly before the layers were coated. Then, after compositions which are the subject of copending U.S. the layers were cast, they were chill-set and dried con- Pat. application Ser. No. 358,237,, filed concurrently ventionally. herewith.

Table l A% Swell Swell Sample 7 Day Check 7 Day lnc. In-

No. Hardener (mm/g gel) 5C/50% RH 49C/50% RH crease +0.044 I98 190 11 9 formaldehyde 0.334 175 200 25 i0 (controhnone 589 492 97 11 11 0.044 250 229 21 12 1 0.067 276 313 37 13 1+ 11 0.033

+0.144 229 213 16 111 v1 0.030 279 342 63 I) Vl 0.059 232 287 20 11 v1 0.022

+0030 203 210 -7 22 II VI 0.022

0.039 305 205 30 1v 0.019 462 369 93 31 1+ IV 0.033

Table 1 Continued A% Swell Swell Sample 7 Day Check 7 Day Inc. In-

No. Hardener (mm/g gel) C/50% RH 49C/50% RH crease 32 l IV 0.067

. 0.019 318 305 13 33 V" 0.333 I70 227 57 34 ll VII 0.022

0.333 168 I6] 7 35 II V" 0.044

0.333 I66 I68 2 36 VIII 0.059 v 405 271 I34 37 l Vlll 0.033

0.059 325 233 92 38 l Vlll 0.067

Results of tests on these photographic elements carried out in an actual commercial photographic film development process (the Kodak Ektachrome ME-4 Process. but without the prehardener and neutralizer steps) at a temperature of 52C conform very well with the data appearing in Table l, above. Also, photographic tests involving conventional exposure on Eastman 18 Sensitometer and then processing the film conventionally revealed that the synergistic hardener compositions of this invention are not photographically det rimental at ordinary use levels.

The invention has been described in detail with particular reference to preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention.

What is claimed is:

1. In a photographic element comprising a support and at least one layer comprising photosensitive silver halide and at least one layer comprising a reaction product of i. at least one hardenable hydrophilic colloid, and

ii. a hardener composition in a concentration sufficient to increase the melting point of said hydrophilic colloid at least about 5C; the improvement which comprises using as a hardener composition a combination of a. bis(vinylsulfonylmethyl)ether and b. an acrylic hardener selected from the group consisting of diacrylamide, N-methacryloylacrylamide and N,N'-diacryloylurea; the weight ratio of (a) to (b) in said hardener composition being from about 5:1 to about 1:5.

2. A photographic element as in claim 1, wherein said hardenable hydrophilic colloid is gelatin.

3. A photographic element as in claim 2, wherein said acrylic hardener is diacrylamide.

4. A photographic element as in claim 2, wherein said acrylic hardener is N-methylacryloylacrylamide.

5. A photographic element as in claim 2, wherein said acrylic hardener is N,N-diacryloylurea.

6. A photographic element as in claim 2, wherein said weight ratio is from about 3:1 to about 1:3.

7. A photographic element as in claim 1, wherein the weight of said hardener composition in said layer is from about 0.7 to about 3 weight percent, based upon the dried weight of said gelatin.

8. In a photographic emulsion composition containing at least one hardenable hydrophilic colloid, at least one photosensitive silver halide, and a hardener composition in an amount sufficient to increase the melting point of said hydrophilic colloid at least about 5C; the improvement which comprises using as said hardener composition a combination of a. bis(vinylsulfonylmethyl)ether and b. an acrylic hardener selected from the group consisting of diacrylamide, N-methacryloylacrylamide and N,N'-diacryloylurea; the weight ratio of (a) to (b) in said hardener composition being from about 5:1 to about 1:5. 

1. IN A PHOTOGRAPHIC ELEMENT COMPRISING A SUPPORT AND AT LEAST ONE LAYER COMPRISING PHOTOSENSITIVE SILVER HALIDE AND AT LEAST ONE LAYER COMPRISING A REACTION PRODUCT OF I. AT LEAST ONE HARDENABLE HYDROPHILIC COLLOID, AND II. A HARDENER COMPOSITION IN A CONCENTRATION SUFFICIENT TO INCREASE THE MELTING POINT OF SAID HYDROPHILIC COLLOID AT LEAST ABOUT 5*C; THE IMPROVEMENT WHICH COMPRISES USING AS A HARDENER COMPOSITIION A COMBINATION OF A. BIS(VINYLSULFONYLMETHYL)ETHER AND B. AN ACRYLIC SELECTED FROM THE GROUP CONSISTING OF DIACRYLAMIDE, N-METHACRYLOYLACRYLAMIDE AND N,N''DIACRYLOYLUREA; THE WEIGHT RATIO OF (A) TO (B) IN SAID HARDENER COMPOSITION BEING FROM ABOUT 5:1 TO ABOUT 1:5.
 2. A photographic element as in claim 1, wherein said hardenable hydrophilic colloid is gelatin.
 3. A photographic element as in claim 2, wherein said acrylic hardener is diacrylamide.
 4. A photographic element as in claim 2, wherein said acrylic hardener is N-methylacryloylacrylamide.
 5. A photographic element as in claim 2, wherein said acrylic hardener is N,N''-diacryloylurea.
 6. A photographic element as in claim 2, wherein said weight ratio is from about 3:1 to about 1:3.
 7. A photographic element as in claim 1, wherein the weight of said hardener composition in said layer is from about 0.7 to about 3 weight percent, based upon the dried weight of said gelatin.
 8. In a photographic emulsion composition containing at least one hardenable hydrophilic colloid, at least one photosensitive silver halide, and a hardener composition in an amount sufficient to increase the melting point of said hydrophilic colloid at least about 5*C; the improvement which comprises using as said hardener composition a combination of a. bis(vinylsulfonylmethyl)ether and b. an acrylic hardener selected from the group consisting of diacrylamide, N-methacryloylacrylamide and N,N''-diacryloylurea; the weight ratio of (a) to (b) in said hardener composition being from about 5:1 to about 1:5. 